InfoPath Dev

I create the info path form and publish to SharePoint Document Library in this form i add drop-down list box and bind the value to this dropdown from SharePoint list. when i open using infopath filler that time value is show in drop down but when i open the form using browser that time not showing value.

 Are there any errors when you open the form? I would probably drag the secondary data source that provides the dropdown values onto the form (temporarily) so that I could see if data was being returned, in order to try to narrow this down. Maybe add a button that queries the data source to see what happens if you query it after the form loads.